Sorting the sequential arrangement of radiation treatment beams regarding well-distributed unobstructed lines of sight

1. A method for determining a positional pattern of an irradiation unit for irradiating a patient with treatment radiation, the irradiation unit being part of an irradiation treatment system including at least one processor, an imaging device for generating a medical image of the patient, and the irradiation unit, the method comprising: a) acquiring, by the at least one processor, irradiation unit position data describing irradiation unit positions of the irradiation unit for which the imaging device has a free viewing direction onto a position of the patient, wherein the free viewing direction onto the position of the patient is a free line of sight from the imaging device to the position of the patient; b) determining, by the at least one processor and based on the irradiation unit position data, position orders data describing all possible ordered sequences of the irradiation unit positions described in the irradiation unit position data; c) determining, by the at least one processor and based on the irradiation unit position data and the position orders data and for each of the possible ordered sequences described by the position orders data, intersection angle data describing a statistical quantity of intersection angles between respective free viewing directions of the imaging device for irradiation unit positions that are neighboring each other in each of the possible ordered sequences described by the position orders data d) determining, by the at least one processor and based on the intersection angle data and the position orders data, optimal order data describing an optimal order, the optimal order being a particular ordered sequence of the irradiation unit positions for which a respective statistical quantity of the particular ordered sequence reaches an optimal predetermined value, or, on a condition that respective statistical quantities of more than one ordered sequence of the irradiation unit positions reach the optimal predetermined value, an ordered sequence, of the more than one ordered sequence having the respective statistical quantities reaching the optimal predetermined value, that satisfies a secondary criterion is determined as the optimal order, wherein, if more than one ordered sequence of the irradiation unit position data satisfy the secondary criterion in addition to reaching the optimal predetermined value, an ordered sequence that further satisfies a tertiary criterion is determined as the optimal order, wherein the tertiary criterion relates to an amount of time for moving the irradiation unit through an order of positions, and wherein the ordered sequence determined as the optimal order satisfies the tertiary criterion when associated with a smallest amount of time for moving through the order of positions; and e) determining, by the at least one processor and based on the optimal order data, control signal data for controlling the imaging unit to attain imaging positions in an order described by the optimal order data.

2. The method according to claim 1 , wherein the irradiation unit position data is predetermined and has been generated on a basis of treatment plan data describing an irradiation treatment plan defining treatment positions that are relative positions between the irradiation treatment device and a treatment body part of the patient at which the treatment radiation shall be emitted.

3. The method according to claim 1 , wherein the imaging device comprises two imaging units.

4. The method according to claim 3 , wherein the two imaging units each are one of an x-ray device, an infrared-sensitive imaging device, or a range camera device.

5. The method according to claim 1 , wherein the free line of sight is not impeded by a part of the irradiation unit.

6. The method according to claim 1 , wherein the irradiation unit position data is predetermined and has been generated on a basis of device geometry data describing an operational geometry of device components which comprise the irradiation treatment device.

7. The method according to claim 1 , wherein the statistical quantity is a sum of the intersection angles, or an average of the intersection angles.

8. The method according to claim 1 , wherein the intersection angles consist of obtuse angles and right angles or wherein the intersection angles consist of acute angles and right angles.

9. The method according to claim 1 , wherein the intersection angles define a field of view of the imaging device between pairwise adjacent irradiation unit positions.

10. The method according to claim 1 , wherein the imaging device comprises at least two imaging units, and wherein the irradiation unit positions are positions of the irradiation unit for which one of the at least two imaging units is unobstructed or wherein the irradiation unit positions are positions of the irradiation unit for which each of the at least two imaging units are unobstructed.

11. The method according to claim 10 , comprising: determining, based on the irradiation unit position data, stereo-imaging data describing the irradiation unit positions for which all of the at least two imaging units are unobstructed, and wherein the optimal order data is determined based on the stereo-imaging data.

12. The method according claim 10 , comprising: determining, based on the irradiation unit position data and by the at least one processor, imaging unit control data describing a control signal for controlling only one of the at least two imaging units that is unobstructed to take an image.

13. The method according to claim 1 , comprising: issuing, by the at least one processor, the control signal data for controlling the imaging unit to attain the imaging positions in the order described by the optimal order data; and controlling, by the at least one processor, the imaging unit according to the control signal data.

14. The method according to claim 1 , wherein the secondary criterion relates to a standard deviation of the respective statistical quantity, and wherein an ordered sequence satisfies the secondary criterion when associated with a smallest standard deviation of the respective statistical quantity.

15. A non-transitory computer-readable storage medium having instructions stored thereon, which, when executed by at least one processor of an irradiation treatment system including an irradiation unit for irradiating a patient with treatment radiation and an imaging device for generating a medical image of the patient, causes the at least one processor to perform the steps comprising: a) acquiring, by the at least one processor, irradiation unit position data describing irradiation unit positions of the irradiation unit for which the imaging device has a free viewing direction onto a position of the patient, wherein the free viewing direction onto the position of the patient is a free line of sight from the imaging device to the position of the patient; b) determining, by the at least one processor and based on the irradiation unit position data, position orders data describing all possible ordered sequences of the irradiation unit positions described in the irradiation unit position data; c) determining, by the at least one processor and based on the irradiation unit position data and the position orders data and per each ordered sequence described by the position orders data, intersection angle data describing a statistical quantity of intersection angles between respective free viewing directions of the imaging device for irradiation unit positions that are adjacent to each other in each ordered sequence described by the position orders data; d) determining, by the at least one processor and based on the intersection angle data and the position orders data, optimal order data describing an optimal order, the optimal order being a particular ordered sequence of the irradiation unit positions for which a respective statistical quantity reaches an optimal predetermined value, or, on a condition that respective statistical quantities of more than one ordered sequence of the irradiation unit positions reach the optimal predetermined value, an ordered sequence, of the more than one ordered sequence having the respective statistical quantities reaching the optimal predetermined value, that also satisfies a secondary criterion is determined as the optimal order, wherein, if more than one ordered sequence of the irradiation unit position data satisfy the secondary criterion in addition to reaching the optimal predetermined value, an ordered sequence that further satisfies a tertiary criterion is determined as the optimal order, wherein the tertiary criterion relates to an amount of time for moving the irradiation unit through an order of positions, and wherein the ordered sequence determined as the optimal order satisfies the tertiary criterion when associated with a smallest amount of time for moving through the order of positions; and e) determining, by the at least one processor and based on the optimal order data, control signal data for controlling the imaging unit to attain imaging positions in an order described by the optimal order data.

16. The non-transitory computer-readable storage medium of claim 15 , wherein the instructions cause the at least one processor to perform the additional steps of: issuing, by the at least one processor, the control signal data for controlling the imaging unit to attain the imaging positions in the order described by the optimal order data; and controlling the imaging unit according to the control signal data.

17. A system for determining a positional pattern of an irradiation unit for irradiating a patient with treatment radiation, the system comprising an irradiation treatment device including, at least one processor, the irradiation unit, and an imaging device for generating a medical image of the patient, wherein the at least one processor is configured to: a) acquire irradiation unit position data describing irradiation unit positions of the irradiation unit for which the imaging device has a free viewing direction onto a position of the patient, wherein the free viewing direction onto the position of the patient is a free line of sight from the imaging device to the position of the patient; b) determine, based on the irradiation unit position data, position orders data describing all possible ordered sequences of the irradiation unit positions described in the irradiation unit position data; c) determine, based on the irradiation unit position data and the position orders data and per each ordered sequence described by the position orders data, intersection angle data describing a statistical quantity of intersection angles between respective free viewing directions of the imaging device for irradiation unit positions that are adjacent to each other in each ordered sequence described by the position orders data; d) determine, by the at least one processor and based on the intersection angle data and the position orders data, optimal order data describing an optimal order, the optimal order being a particular ordered sequence of the irradiation unit positions for which a respective statistical quantity reaches an optimal predetermined value, or, on a condition that respective statistical quantities of more than one ordered sequence of the irradiation unit positions reach the optimal predetermined value, an ordered sequence, of the more than one ordered sequence having the respective statistical quantities reaching the optimal predetermined value, that satisfies a secondary criterion is determined as the optimal order, wherein, if more than one ordered sequence of the irradiation unit position data satisfy the secondary criterion in addition to reaching the optimal predetermined value, an ordered sequence that further satisfies a tertiary criterion is determined as the optimal order, wherein the tertiary criterion relates to an amount of time for moving the irradiation unit through an order of positions, and wherein the ordered sequence determined as the optimal order satisfies the tertiary criterion when associated with a smallest amount of time for moving through the order of positions; and e) determine, by the at least one processor and based on the optimal order data, control signal data for controlling the imaging unit to attain imaging positions in an order described by the optimal order data.

18. The system of claim 17 , wherein the at least one processor is further configured to: issue the control signal data for controlling the imaging unit to attain the imaging positions in the order described by the optimal order data; and control the imaging unit according to the control signal data.